Blast furnace charging systems



Sept. 1, 1959 5 sc ETAL 2,902,179

, BLAST FURNACE CHARGING SYSTEMS Filed March 3, 1955 4 Sheets-Sheet l ERIK TORSTEN ANDERSON TESCH a 'ISAK EDVIN JOHANSSON ATTORNEYS Sept. 1, 1959- E Esc ETAL 2,902,179

BLAST FURNACE CHARGING SYSTEMS Filed March 3, 1955 I 4 Sheets-Sheet 2 r rr r I F 3 INVENTORS ERIK TORSTEN ANDERSON TESCH G ISAK EDVIN J'OHAN$ $ON $1M, ,s M 41W ATTORIjElS Sept. 1, 1959 E. T. A. TEscH ETAL' 2,902,179

BLAST FURNACE CHARGING SYSTEMS Filed March a, 1955' 4 Sheets-Sheet s /7// I r///, I

Fl INVENTORS ERIK TORSTEN ANDERSON TESCH &

ISAK EDVIN JOHANSSON ATTO RNEYS Sept. 1, 1959 scH ET AL. 2,902,179

BLAST FURNACE CHARGING SYSTEMS- Filed March 5, 1955 4 Sheets-Sheet 4 lhhhhhhl ll FIG. 6. 27

INVENTORS ERIK TORSTEN ANDERSON TESCH 8 ISAK EDVIN J'OHANSSON ATTOR N EYS United States Patent 9 BLAST FURNACE CHARGING SYSTEMS Erik Torsten Anderson Tesch and Isak Edvin .lohansson,

Stockholm, Sweden, assignors to T. An. Tesch Aktiebolag, Stockholm, Sweden, a corporation of Sweden Application March 3, 1955, Serial No. 491,981 Claims priority, application Sweden March 15, 1954 4 Claims. (Cl. 214-36) The present invention relates to systems for charging shaft furnaces particularly blast furnaces, havinge a charging device comprising two hoppers with associated closing bells and also a charge distributing bell, said system including an actuating member adapted, after dumping a charge unit into the upper hopper, to initiate the action of driving means for opening and closing the upper bell. The object of this invention is to provide a completely automatic charging operation in accordance with a predetermined charging sequence or program. It is also an object of the invention to provide for the most uniform possible distribution of the charge across the entire area of the furnace opening.

In accordance with this invention these objects are achieved thereby that the driving means of the upper bell is adapted to operate a control member so that said control member, in accordance with a predetermined adjustment thereof in conformity with the selected charging sequence, will initiate the action of driving means adapted to open and close the lower bell, after a predetermined number of charge units have been introduced into the lower hopper, whereupon said control member, or a second control member controlled by the first control member, in accordance with the selected sequence will operate driving means adapted to lift or lower the distributing bell, said control member or members comprising stepwise rotatable rotors having engaging members positioned in accordance with the selected charging sequence and adapted to initiate the driving means for the lower bell and the distributing bell respectively in the desired sequence.

If the top portion of the furnace shaft includes a double stock distributor the distributing bell may be adapted to operate a separate control member, which initiates a separate driving means when, in accordance with the selected charging program, the distributing bell is to be lowered into a position, in which it closes the central opening of the stock distributor.

The accompanying drawings illustrate, by way of example, some embodiments of the invention.

On the drawings:

Figs. 1 and 2 illustrate in partial longitudinal crosssection a shaft furnace having two hoppers and closing bells and a distributing bell.

Fig. 3 shows a similar cross-section through a furnace comprising in addition to the above-mentioned hoppers and bells a simple stock distributor.

Fig. 4 shows a furnace comprising a double stock distributor.

Fig. 5 illustrates diagrammatically a control system intended for the furnace according to Fig. 4 and comprising operating members and driving means consisting of hydraulic devices.

Fig. 6 illustrates a portion of the operating members in Fig. 4 in top plan view.

The shaft furnace is shown at A, the lower hopper of the charging device at B and the upper hopper thereof at C. The letter D (Fig. 3) designates a simple stock distributor provided in the upper portion of the furnace A, while the letters D, E (Fig. 4) designate a double stock distributor.

The materials to be charged into the furnace are delivered to the furnace top in the skip car 1.

After a suitable quantity of stock has been supplied to'the hopper C, which is shown rotatably supported on rollers 2, the conical bell 3 is lowered to the position indicated at 3 and is then returned to the closed position after the stock has dropped into the hopper B.

After a predetermined number of loads have been dumped into the hopper B, the stock is dumped from the hopper B into the furnace A. This is made by lifting the bell 4 to its upper position 4'. After the material has dropped into the furnace, the bell 4 is lowered into its lower or seated position.

The lowest bell 5 can be lifted into the upper position 5' or lowered into the lower position 5 (Figs. l-3) or into either of the two lower positions 5" and 5' (Fig. 4).

When the distributing bell is lifted into the position 5 the bell 5 accompanies the bell 4 and the material in the hopper B drops into the central portion of the furnace A. When the bell 5 is lowered into the position 5" prior to or simultaneously with the lifting of the bell 4, the material pours laterally and downwardly along the outer surface of the bell 5 in the position 5" and, according to Fig. 3, further along the surface of the simple stock distributor D and is distributed around the circumference of the furnace.

According to Fig. 4 there is another stock distributor E disposed in the upper portion of the shaft. When the bell 5 is lowered into the position 5" the dropping charge spreads from the hopper B along the bell 5 (in the position 5') and further along the top surface of the charge distributor E and is distributed concentrically in an intermediate Zone between the circumference and the center of the furnace.

The lifting and lowering movements of the bells are performed by means of fluid pressure cylinders containing pistons and communicating through pipes 8 having shut-off valves with the pressure fluid pump 9 and the collecting tank 10.

The bell 3 is operated by the fluid pressure cylinder 11 and piston 12. A counterweight 13 serves to balance the weight of the bell 3 in such a manner that the lifting movement of the bell takes place without the use of fluid pressure.

The bell 4 is operated by a fluid pressure cylinder 14 and piston 15.

The bell 5 according to Figs. 1 to 3 is operated solely by the fluid pressure cylinder 16 and piston 17. A counterweight 18 serves to balance the weight of the bell 5 in such a manner that the lifting movement of the bell is performed without the use of fluid pressure.

According to Fig. 4, on the other hand, the bell 5 is operated by the fluid pressure cylinder 16 and piston 17 which serve to lower the bell 5 into the positions 5 and 5" and also by an electrical aggregate 21 serving to lower and lift the bell between the positions 5 and 5" in that the electrical machinery lifts and lowers the fluid pressure cylinder 16. The counterweight 18 serves to effect the upward movement of the bell 5 from the position 5" to the position 5.

The trans-mission of power between the fluid pressure cylinders and the bells is effected by means of cables 23 and sheaves 24.

The numeral 25 represents generally an electric switching device which, if desired over an electric time delay relay, starts the driving means, in this case the pump unit 9, and opens shut-off valve 41 so that pressure fluid is supplied to the cylinder 11 and the piston 12, whereby 3 the hell 3 is lowered and the material in the hopper C is dumped in the hopper B. The electric switching means 25 is actuated by the device for dumping the material into the hopper C, in this case the skip car 1. When the piston 12 has reached its top position, it actuates suitable means (not shown) such as an electric switch, which stops the pump 9. Due to the pressure of the piston, the fluid then returns through the pipes 8 and the pump 9 and the bell 3 reverts to its closing position. When the piston reaches its bottom position, it actuates another switch (not shown), which closes the valve 41.

Instead of hydraulic or pneumatic cylinders to operate the bells, a purely electric operating system may be devised a well-known manner. Also, the operating means for the bells may be placed on the furnace top and the cables be replaced by levers.

The automatic operation of the system will now be described in detail.

The operation of the bell 4 is performed automatically in the following manner:

The piston rod 6 of the piston 12 carries a pawl 26 which, when the piston makes an upward and downward stroke, turns a ratchet wheel 27 through an angle corresponding to the angular spacing between two ratchet wheel teeth. The ratchet wheel 27 is secured to a circular disc 28 and along the circumference thereof there are detachably affixed engaging members or pins 29. When angular displacement of the disc 28 through a sufficient number of steps has taken place, so that an engaging pin 29 engages a tooth in a ratchet wheel 3%, this ratchet wheel is turned through an angle equal to the angular spacing between two teeth thereof as the pin 29 passes the engaging position.

The ratchet wheel 3% in its turn is aflixed to a disc 31 which is turned an amount equal to that of the ratchet Wheel 30. Along and around the disc 31 there are provided a number of detachable engaging members or pins 32 so disposed that, as the disc 31 turns through an angle equal to that of the tooth spacing on the ratchet wheel 30, a pin 32 actuates an electric switching device 33, which if desired via an electric time-delay relay, energizes the driving means, in this case the pump unit 3 and opens shutoff valve 42 to supply fluid to the fluid pressure cylin'd'er 14 and piston 15, so that the bell 4 is lifted and the charge in the hopper B is dumped in the furnace A. At the same time, the bell is raised into position 5' due to the fact that the counterweight 18 causes the hell '5 to accompany bell 4. When the piston 15 reaches its bottom position, it actuates a switch (not shown) which stops the pump, so that the bells 4 and 5 return into their initial position, the piston 15 driving out the fiuid through pipes 8 and pump 9. When the piston reaches its top position, it actuates another switch which closes valve 42.

To initiate the movement of the distributor bell 5, into position 5, a number of pins 34 are detachably mounted on the side of the disc 31 opposite to that carrying the pins 32 and may be inserted in all or in some of the positions corresponding to those of the pins 32.

An electric switching device 35 is so arranged that when the pins 34 pass the switching device 35, due to the step-wise angular movement of the disc 31, the pins 34 actuate this device 35 to open valve 43 and thus (since the pump 9 is started by switching device 33) supply fluid to the fluid pressure cylinder 16 and piston 17, so that the distributing bell is moved to the position 5". When the pump 8 is stopped, the bell reverts to its initial position, since the pressure of the piston 17 drives out the fluid through pipe 8 and pump 9. Thereupon, the valve 43 is closed by suitable means actuated by piston 17.

Automatic initiation of the movement of the bell 5 to bring it into the position 5" by means of the electric driving means 21 is effected by the following arrangement:

'On the piston rod 7 of the piston 17 there is secured a pawl 36 which, when the piston makes an upward and downward stroke, turns a ratchet Wheel 37 by an amount corresponding to the angular spacing between a pair of ratchet wheel teeth. The ratchet wheel 37 is secured to a disc 38 and around its circumference there are provided a number of engaging members or pins 39. These may be affixed in all or some of the positions shown on the disc 38.

An electric switching device 44 is so arranged that as the engaging pins 39 pass the switching device 40, due to the step-wise rotation of the disc 38, the pins 39 actuate this device 49 to start the electric driving means 21, Whereby the cylinder 16 is lowered or lifted to move the distributing bell between the positions 5 and 5".

In the arrangement of this invention, the engaging members 29, 34 and 39 and, if desired, also 32, may easily be inserted in such positions that the particular desired sequence of distribution of charges in the furnace is attained, if desired in V conjunction with a suitable choice of the number of charge units dumped from the upper hopper C into the lower hopper B between each dumping into the furnace itself. The sequence and its continued recurrence will not be dependent on the work of operators and their greater or lesser efliciency. The automatic control system for the embodiments of Figures 1 and 3 is similar to that described above except that the motor 21 and the members lid-40 for its operation are excluded.

The principle of this invention may of course be embodied in other mechanical means than these shown and described above. Thus the control members and the electric contact means may be devised in any suitable manner and adapted to any desired driving means other than fluid pressure cylinders for the bells.

As an example, the following charging sequence may ben mentioned.

Each time that the upper hopper C receives a carload, the upper hell 3 is opened so that this load is dumped into the lower hopper. The control means may be so constructed and adjusted, e.g. in the case of charging a furnace as shown in Figure 4 where the material is to be introduced into the furnace alternatingly along the shaft wall, centrally and in an intermediate zone, that the lower hopper B, when the charge is to be placed along the wall, is emptied, e.g. after introducing four loads from the hopper C. The distributing hell 5 is then brought into the position 5" so that the material flows along the outer stock distributor D. To introduce the material into the furnace A in a zone between the furnace wall and the central portion of the furnace, the control means are so adjusted that the bell 4 is opened after supplying three loads to the hopper B. The bell 5 is then lowered into the position 5" so that the material passes through thei annual passage between the stock distributors D an When it is desired to introduce the charge centrally, the hell 4 of the lower hopper B is lifted after two loads have been dumped thereinto from the upper hopper C. The bell 5 is then lifted to the position 5 so that the material falls from the hopper B through the central openings of the two charge distributors D, E.

Having now particularly described the nature of our invention and the manner of its operation what we claim is:

1. Fu'rnace charging apparatus comprising a lower charging hopper, a closing bell for said lower hopper, an upper charging hopper emptying into said lower hopper, a closing bell for said upper hopper, a stock distributing bell positioned below said lower hopper closing bell, means for operating said upper closing bell, and means responsive to a predetermined number of operations of said upper closing bell for operating said lower closing and distributing bells automatically in predetermined sequence including a train of rotary members, means operatively connecting the input member of said train of rotary members with said upper closing bell for intermittent operation by the latter, and means operatively connecting the output member of said train of rotary members with said lower closing and distributing bells including a pair of electric switches respectively associated with said lower closing and distributing bells and controlled by the output member of said train of rotary members.

2. Furnace charging apparatus as defined in claim 1 wherein the input member of the train of rotary members is provided with a first set of detent elements, the means operatively connecting said input member with said upper closing bell includes an element engageable between the detents of said first set of detents for progressively actuating said train of rotary members in response to operation of said upper closing bell, the output members of the train of rotary members is provided with a second and a third set of detent elements respectively controlling the electric switches, and the detents of said second and third sets thereof are selectively mountable upon said output member in a plurality of different patterns.

3. Furnace charging apparatus comprising a lower charging hopper, a closing bell for said lower hopper, an upper charging hopper emptying into said lower hopper, a closing bell for said upper hopper, a stock distributing bell positioned below said lower hopper closing bell, means for operating said hopper closing bell, means responsive to a predetermined number of operations of said upper closing bell for operating said lower closing and distributing bells including a train of rotary members, means operatively connecting the input member of said train of rotary members with said upper closing bell for intermittent operation by the latter, means operatively connecting the output member of said train of rotary members with said lower closing and distributing bells including a pair of electric switches respectively associated with said lower closing and distributing bells and controlled by the output member of said train of rotary members, auxiliary means responsive to a predetermined number of operations of said distributing bell for further operating the same including auxiliary rotary means,

6 means operatively connecting the input member of said auxiliary rotary means with said distributing bell for intermittent operation by the latter, and means operatively connecting the output member of said auxiliary rotary means with said distributing bell including an electric switch controlled by the output member of said auxiliary rotary means, the first mentioned and auxiliary responsive means being operative conjointly to automatically operate said lower closing and distributing bells in predetermined sequence.

4. Furnace charging apparatus as defined in claim 3 wherein the input member of the train of rotary members is provided with a first set of detent elements, the means operatively connecting said input member With said upper closing bell includes an element engageable between the detents of said first set of detents for progressively actuating said train of rotary members in response to operation of said upper closing bell, the output member of the train of rotary members is provided with a second and a third set of detent elements respectively controlling the associated electric switches, the input member of the rotary means is provided with a fourth set of detent elements, the means operatively connecting said rotary means input member with said distributing bell includes an element engageable between the detents of said fourth set of detents for progressively actuating said rotary means in response to operation of said distributing bell, the output member of said rotary means is provided with a fifth set of detent elements controlling the associated electric switch, and the detents of the second, third and fifth sets thereof are selectively mountable upon the associated output members in a plurality of dilferent patterns.

References Cited in the file of this patent UNITED STATES PATENTS 864,053 Witherbee Aug. 20, 1907 2,096,567 Smith Oct. 19, 1937 2,250,852 Bertelsen July 29, 1941 2,667,278 Tesch et a1. Jan. 26, 1954; 

